Chemistry Commons^™

Improved Synthesis Of Pincer Ligand Precursor, And Synthesis And Structural Characterization Of Terphenyl Scaffolded S–C–S Palladium Pincer Complex., Paul Schroder, Thomas Spilker, Wilson Luu, James Updegraff, Man Lung Kwan, Paul Challen, John Protasiewicz

Man Lung Desmond Kwan

An easier and more expedient synthesis of 2,6-(BrCH2C6H4)2-4-I-C6H3 (2) is reported. This material allowed easy synthesis of the new pincer ligand precursor 2,6-(4-CH3C6H4SCH2C6H4)2-4-I-C6H3 (3) in 87% yield. Compound 3 reacts with Pd2(dba)3 to give the new palladium pincer complex 4. Compound 4 has been fully characterized, including structural characterization by single crystal X-ray diffraction methods. The results of the crystallographic work on 4 reveal a twisted type pincer complex not unlike related terphenyl pincer complexes.

Improved Synthesis Of Pincer Ligand Precursor, And Synthesis And Structural Characterization Of Terphenyl Scaffolded S–C–S Palladium Pincer Complex., Paul Schroder, Thomas Spilker, Wilson Luu, James Updegraff, Man Lung Kwan, Paul Challen, John Protasiewicz

Paul R. Challen

An easier and more expedient synthesis of 2,6-(BrCH2C6H4)2-4-I-C6H3 (2) is reported. This material allowed easy synthesis of the new pincer ligand precursor 2,6-(4-CH3C6H4SCH2C6H4)2-4-I-C6H3 (3) in 87% yield. Compound 3 reacts with Pd2(dba)3 to give the new palladium pincer complex 4. Compound 4 has been fully characterized, including structural characterization by single crystal X-ray diffraction methods. The results of the crystallographic work on 4 reveal a twisted type pincer complex not unlike related terphenyl pincer complexes.

Optimizing Harvest Of Corn Stover Fractions Based On Overall Sugar Yields Following Ammonia Fiber Expansion Pretreatment And Enzymatic Hydrolysis, Rebecca G. Ong, Shishir Ps Chundawat, Venkatesh Balan, Bruce E. Dale

Rebecca Ong

Zincast-1: A Photochemically Active Chelator For Zn2+, Shawn Burdette, Celina Gwizdala, Daniel Kennedy

Shawn C. Burdette

Two strategies were applied to the synthesis of ZinCast-1, a nitrobenzhydrol-based caged complex that upon photolysis exhibits a nearly 400-fold difference in binding for Zn2+.

Experimental And Theoretical Study Of The Structures And Enthalpies Of Formation Of The Synthetic Reagents 1,3-Thiazolidine-2-Thione And 1,3-Oxazolidine-2-Thione., María Victoria Roux, Manuel Temprado, Pilar Jiménez, Concepción Foces-Foces, Rafael Notario, Archana R. Parameswar, Alexei V. Demchenko, James S. Chickos, Carol A. Deakyne, Alicia K. Ludden, Joel F. Liebman

James Chickos

No abstract provided.

Absolute Nitrogen Atom Density Measurements By Two-Photon Laser-Induced Fluorescence Spectroscopy In Atmospheric Pressure Dielectric Barrier Discharges Of Pure Nitrogen, Et-Touhami Es-Sebbar, Christian Sarra-Bournet, Nicolas Naudé, Françoise Massines, Nicolas Gherardi

Dr. Et-touhami Es-sebbar

In this paper, two-photon absorption laser induced fluorescence spectroscopy is used to follow the nitrogen atom density in flowing dielectric barrier discharges fed with pure nitrogen and operating at atmospheric pressure. Two different dielectric barrier discharge regimes are investigated: the Townsend regime, which is homogeneous although operating at atmospheric pressure, and the more common filamentary regime. In both regimes, densities as high as 3x1014 /cm3 are detected. However, the N atoms kinetic formation depends on the discharge regime. The saturation level is reached more rapidly with a filamentary discharge. For a given discharge regime, the N atom density depends strongly …

Contributions To The Development Of The S.E.T.U.P. (Experimental And Theoretical Simulations Useful For Planetology) Project, E. Arzoumanian, C. Romanzin, M-C. Gazeau, Et. Es-Sebbar, A. Jolly, S. Perrier, Y. Benilan

Dr. Et-touhami Es-sebbar

No abstract provided.

Multiwavelength Studies For Titan's Atmospheric Composition Analysis, Y. Benilan, Et. Es-Sebbar, N. Fray, M-C. Gazeau, A. Jolly, M. Schwell, J. Guillemin

Dr. Et-touhami Es-sebbar

Titan's atmosphere mainly made of nitrogen and methane is rich in organic molecules. Hydrocarbons are formed from the photolytic dissociation of CH4 and nitriles are created by dissociation of N2 followed by reactions with hydrocarbons. In order to understand the physicochemical mechanisms responsible for the evolution of Titan's atmosphere, photochemical models are built. The latter need constrains for vertical profiles of organic compounds from the high thermosphere down to the low stratosphere as well as photodissociation rates. Those profiles over the entire atmosphere can be retrieved from Cassini observations, in particular by limb sounding, coupling infrared and ultraviolet spectroscopy. However, …

Vuv Photostability Of Prebiotic Species, M. Schwell, Y. Bénilan, M.-C. Gazeau, N. Fray, A. Jolly, Et. Es-Sebbar, N. Champion, S. Leach, H. W Jochims, H. Baumgärtel, E. Rühl

Dr. Et-touhami Es-sebbar

No abstract provided.

S.E.T.U.P. Experimental And Theoretical Simulations Useful For Planetology- Related Studies In The Frame Of A Program Of Titan’S Atmosphere Laboratory Simulations, M.-C. Gazeau, Et. Es-Sebbar, E. Arzoumanian, C. Romanzin, A. Jolly, S. Perrier, Y. Bénilan

Dr. Et-touhami Es-sebbar

No abstract provided.

Impedance Differences Found With N-Alkanethiol Monolayers Prepared By Contact Printing And Solution Adsorption, Leslie Adamczyk, Mark Anderson

Mark R. Anderson

Self-assembled monolayers (SAMs) of n-octadecanethiol, n-dodecanethiol and n-pentanethiol formed by contact printing and solution adsorption are characterized by electrochemical impedance spectroscopy (EIS). Impedance measurements show that monolayers prepared by contact printing are on the order of 5 times less resistive to charge transfer and have greater defect density than monolayers prepared by solution adsorption. Modeling of the average defect size and density show that the size of monolayer defects stays relatively constant independent of the monolayer preparation conditions; however, the density of defects decreases with increasing concentration for the contact printed monolayers. The impedance data also show that monolayers prepared …

The Spectroelectrochemical, Magnetic, And Structural Characterization Of Reduced Hexaazatriphenylenehexacarbonitrile, Hat(Cn)6., Joseph Gallegos, Anthony Francis, Nathan Ockwig, Paul Rasmussen, Raphael Raptis, Paul Challen, Issouf Ouedraogo

Paul R. Challen

The cyanoazacarbon, hexaazatriphenylenehexacarbonitrile, or HAT(CN)6, is readily reduced and the spectroelectrochemical properties associated with the multiple reductions are described. The singly reduced radical monoanion forms stable salts and we report the crystal structure and magnetic properties for the tetrabutylammonium salt. [Tetra-n-butylammonium] [HAT(CN)6] behaves ferromagnetically below 3K and follows Curie Law behavior at higher temperatures after correction for Pauli-type susceptibility. The room temperature conductivity of the powdered salt is 3.8×10−8S/cm. The crystal structure shows closely bound pairs of radical anions with slip-stacking of these pairs to form a staircase, features that elucidate the observed properties. Thin films of HAT(CN)6 were found …

Ligand-Dependent Effects On The Conformational Equilibrium Of The Na+,K+-Atpase As Monitored By Voltage Clamp Fluorometry, Robert Dempski, Stefan Geys, Ernst Bamberg

Robert E. Dempski

Voltage clamp fluorometry was used to monitor conformational changes associated with electrogenic partial reactions of the Na(+),K(+)-ATPase after changes in the concentration of internal sodium (Na(+)(i)) or external potassium (K(+)(o)). To probe the effects of the Na(+)(i) concentration on the Na(+) branch of the Na(+),K(+)-ATPase, oocytes were depleted of Na(+)(i) and then loaded with external sodium (Na(+)(o)) using the amiloride-sensitive epithelial sodium channel. The K(+) branch of the Na(+),K(+)-ATPase was studied by exposing the oocytes to different K(+)(o) concentrations in the presence and absence of Na(+)(o) to obtain additional information on the apparent affinity for K(+)(o). Our results demonstrate that …

Characterization Of An N2 Flowing Microwave Post-Discharge By Oes Spectroscopy And Determination Of Absolute Ground-State Nitrogen Atom Densities By Talif, Et. Es-Sebbar, Y. Benilan, A. Jolly, M-C. Gazeau

Dr. Et-touhami Es-sebbar

A flowing microwave post-discharge source sustained at 2.45 GHz in pure nitrogen has been investigated by optical emission spectroscopy (OES) and two-photon absorption laser-induced fluorescence (TALIF) spectroscopy. Variations of the optical emission along the post-discharge (near, pink and late afterglow) have been studied and the gas temperature has been determined. TALIF spectroscopy has been used in the late afterglow to determine the absolute ground-state nitrogen atomic densities using krypton as a reference gas. Measurements show that the microwave flowing post-discharge is an efficient source of N (4S) atoms in late afterglow. In our experimental conditions, the maximum N (4S) density …

Homologation Of Α-Amino Acids To Β-Amino Acids Via A Modified Arndt-Eistert Synthesis, Brian Brennan, James Carolan, '10

Brian B. Brennan

No abstract provided.

Utilizing Phage Display To Identify Novel Peptides That Bind To Sickle Cell Hemoglobin, Brian Brennan, Chris Betzle, '10

Brian B. Brennan

No abstract provided.

The Development Of A Novel Therapeutic For The Treatment Of Sickle Cell Disease, Brian Brennan, Steven Sturlis, '10

Brian B. Brennan

No abstract provided.

Novel Therapeutics In The Treatment Of Sickle Cell Disease: Expression And Purification Of Hemoglobin And Sickle Cell Hemoglobin, Brian Brennan, Susan Zhong, '11

Brian B. Brennan

No abstract provided.

Utilizing Phage Display To Identify Novel Peptides That Bind To Sickle Cell Hemoglobin, Brian Brennan, Chris Betzle, '10

Brian B. Brennan

No abstract provided.

The Synthesis And Characterization Of A Peptide Hemoglobin Ligand, Brian Brennan, Chris Brackett, '11

Brian B. Brennan

No abstract provided.

The Synthesis Of A Peptoid For Use As A Novel Therapeutic In The Treatment Of Sickle-Cell Disease, Brian Brennan, Michael Chiodo, '11

Brian B. Brennan

No abstract provided.

Simultaneous Quantitation Of Multiple Classes Of Organohalogen Compounds In Fish Oils With Direct Sample Introduction Comprehensive Two-Dimensional Gas Chromatography And Time-Of-Flight Mass Spectrometry, Eunha Hoh, Steven J. Lehotay, Kristin C. Pangallo, Katerina Mastovska, Helen L. Ngo, Christopher M. Reddy, Walter Vetter

Kristin Pangallo

Capabilities Of Direct Sample Introduction-Comprehensive Two-Dimensional Gas Chromatography-Time-Of-Flight Mass Spectrometry To Analyze Organic Chemicals Of Interest In Fish Oils., Eunha Hoh, Steven J. Lehotay, Katerina Mastovska, Helen L. Ngo, Walter Vetter, Kristin C. Pangallo, Christopher M. Reddy

Kristin Pangallo

Characterization Of Metal-Reducing Enzymes Expressed By The Bacterium Shewanella Algae: Gene Sequencing, Thomas Goyne, Changmo Sohn, Sarah Tesch, Jonathan Penny

Thomas Goyne

No abstract provided.

Electrostatic Deposition Of Polycations And Polyanions Onto Cysteine Monolayers, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy and the quartz crystal microbalance are used to monitor the deposition of polyelectrolytes onto an interface modified with a monolayerofcysteine. When using an anionic redox probe, Fe(CN)−46, the impedance of the cysteine modified electrode is a function of the solution pH; the charge-transfer resistance being higher at basic pH, and smaller under acidic conditions relative to the value found when the solution is buffered near the pI for cysteine. This behavior is consistent with the electrostatic interaction between the anionic redox probe and the net charge of the interface. After exposure of the cysteine-modified interface to 0.10 …

Catena-Poly[[(Pyridine-Κn)Copper(Ii)]-Μ3-Pyridine-2,6-Dicarboxylato-Κ3o2:O2′,N,O6:O6′], Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath

Nigam Rath

Researches On Copper. History & Metallurgy, Fathi Habashi

Fathi Habashi

Gold. History, Metallurgy, Culture, Fathi Habashi

Fathi Habashi

Amphipathic Small Molecules Mimic The Binding Mode And Function Of Endogenous Transcription Factors, Brian Brennan, Sara Buhrlage, Caleb Bates, Steven Rowe, Aaron Minter, Chinmay Majmudar, David Wemmer, Hashim Al-Hashimi, Anna Map

Brian B. Brennan

Small molecules that reconstitute the binding mode(s) of a protein and in doing so elicit a programmed functional response offer considerable advantages in the control of complex biological processes. The development challenges of such molecules are significant, however. Many protein–protein interactions require multiple points of contact over relatively large surface areas. More significantly, several binding modes can be superimposed upon a single sequence within a protein, and a true small molecule replacement must be preprogrammed for such multimodal binding. This is the case for the transcriptional activation domain or TAD of transcriptional activators as these motifs utilize a poorly characterized …

The Effect Of Catalyst Of The Reaction Of P-Hydroxybenzaldehyde With Acetic Anhydride: A Discovery-Oriented Green Laboratory Experiment, Ram Mohan, Matthew Huddle, Michael Devore

Ram S. Mohan

No abstract provided.